Richard Tallent pointed out that XFN could be a key component of building trust networks between blogs. He also had some gripes about the syntax and scope, which is fine, as we don’t envision XFN as being complete by any means and are very keen to see what people suggest. My responses can be found in the comments section of his post.

One of the things I forgot to point out in my announcement yesterday is that not only can you add XFN values to your links, but you can do so and still have your HTML validate— see, for example, the validator report for the main page of meyerweb— because XFN uses an existing HTML attribute (rel) in a way that HTML itself allows. In other words, XFN enhances the Web without breaking it, very much in the spirit of Tim’s original vision of interlocking technologies that worked together to create a social medium. That’s an important aspect of XFN, and one I didn’t want to overlook.

Of course, XFN isn’t constrained to HTML. Any XML language can also use XFN, given the right hooks are included in the language’s DTD. Thus, we’ve created something that works today as well as tomorrow.

We’re still very interested in suggestions and constructive criticism, so keep those posts coming!